2 * armboot - Startup Code for ARM720 CPU-core
4 * Copyright (c) 2001 Marius Gröger <mag@sysgo.de>
5 * Copyright (c) 2002 Alex Züpke <azu@sysgo.de>
7 * See file CREDITS for list of people who contributed to this
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of
13 * the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
32 *************************************************************************
34 * Jump vector table as in table 3.1 in [1]
36 *************************************************************************
42 ldr pc, _undefined_instruction
43 ldr pc, _software_interrupt
44 ldr pc, _prefetch_abort
50 _undefined_instruction: .word undefined_instruction
51 _software_interrupt: .word software_interrupt
52 _prefetch_abort: .word prefetch_abort
53 _data_abort: .word data_abort
54 _not_used: .word not_used
58 .balignl 16,0xdeadbeef
62 *************************************************************************
64 * Startup Code (reset vector)
66 * do important init only if we don't start from memory!
67 * relocate armboot to ram
69 * jump to second stage
71 *************************************************************************
75 * CFG_MEM_END is in the board dependent config-file (configs/config_BOARD.h)
85 * Note: _armboot_end_data and _armboot_end are defined
86 * by the (board-dependent) linker script.
87 * _armboot_end_data is the first usable FLASH address after armboot
89 .globl _armboot_end_data
91 .word armboot_end_data
93 * Note: armboot_end is defined by the (board-dependent) linker script
100 * _armboot_real_end is the first usable RAM address behind armboot
101 * and the various stacks
103 .globl _armboot_real_end
107 #ifdef CONFIG_USE_IRQ
108 /* IRQ stack memory (calculated at run-time) */
109 .globl IRQ_STACK_START
113 /* IRQ stack memory (calculated at run-time) */
114 .globl FIQ_STACK_START
121 * the actual reset code
126 * set the cpu to SVC32 mode
134 * relocate exeception table
146 * we do sys-critical inits only at reboot,
147 * not when booting from ram!
149 #ifdef CONFIG_INIT_CRITICAL
153 /* set up the stack */
155 add r0, r0, #CONFIG_STACKSIZE
156 sub sp, r0, #12 /* leave 3 words for abort-stack */
157 ldr pc,_start_armboot
159 _start_armboot: .word start_armboot
162 *************************************************************************
164 * CPU_init_critical registers
166 *************************************************************************
170 # actually do nothing for now!
175 *************************************************************************
179 *************************************************************************
185 #define S_FRAME_SIZE 72
207 #define MODE_SVC 0x13
211 * use bad_save_user_regs for abort/prefetch/undef/swi ...
212 * use irq_save_user_regs / irq_restore_user_regs for IRQ/FIQ handling
215 .macro bad_save_user_regs
216 sub sp, sp, #S_FRAME_SIZE
217 stmia sp, {r0 - r12} @ Calling r0-r12
221 add r2, r2, #CONFIG_STACKSIZE
223 ldmia r2, {r2 - r4} @ get pc, cpsr, old_r0
224 add r0, sp, #S_FRAME_SIZE @ restore sp_SVC
228 stmia r5, {r0 - r4} @ save sp_SVC, lr_SVC, pc, cpsr, old_r
232 .macro irq_save_user_regs
233 sub sp, sp, #S_FRAME_SIZE
234 stmia sp, {r0 - r12} @ Calling r0-r12
236 stmdb r8, {sp, lr}^ @ Calling SP, LR
237 str lr, [r8, #0] @ Save calling PC
239 str r6, [r8, #4] @ Save CPSR
240 str r0, [r8, #8] @ Save OLD_R0
244 .macro irq_restore_user_regs
245 ldmia sp, {r0 - lr}^ @ Calling r0 - lr
247 ldr lr, [sp, #S_PC] @ Get PC
248 add sp, sp, #S_FRAME_SIZE
249 subs pc, lr, #4 @ return & move spsr_svc into cpsr
253 ldr r13, _armboot_end @ setup our mode stack
254 add r13, r13, #CONFIG_STACKSIZE @ resides at top of normal stack
257 str lr, [r13] @ save caller lr / spsr
261 mov r13, #MODE_SVC @ prepare SVC-Mode
267 .macro get_irq_stack @ setup IRQ stack
268 ldr sp, IRQ_STACK_START
271 .macro get_fiq_stack @ setup FIQ stack
272 ldr sp, FIQ_STACK_START
279 undefined_instruction:
282 bl do_undefined_instruction
288 bl do_software_interrupt
308 #ifdef CONFIG_USE_IRQ
315 irq_restore_user_regs
320 /* someone ought to write a more effiction fiq_save_user_regs */
323 irq_restore_user_regs